FEATURES & BENEFITS ** The only keyhole slot marking tool with a recessed marker – leaves no unwanted marks while positioning an object in contact with the surface ** No measuring or templates needed to mount items with keyhole slots ** Spring-loaded tools hold in place while tightening ** Self-inking marker ** Long-lasting ink (now 5 years) will make more than 1000 very visible marks ** Storage rack holds all components in one place ** Professional quality with metal internal components  WORKS WITH THE MAJORITY OF KEYHOLE SLOT STYLES - Using the included interfaces, the hanging tools work on all keyhole slot materials and most keyhole slot configurations, including molded-in (plastic), cut-in (wood, plastic or metal), add-on hardware (surface mounted or recessed). Accommodates thicknesses ranging from thin metal to 3/8". [See website FAQ for any keyhole slot configuration that creates difficulty].  MARKS VIRTUALLY ANY SURFACE - Comes with non-drying (confirmed so far 5 years) black and white ink to mark both light and dark surfaces. The caps store ample long-lasting ink for more than 1000 uses. Works on hard, soft, smooth, and rough/textured surfaces. Ink marks can be removed with a Magic Eraser or denatured alcohol.           RECESSED, SELF-INKING MARKER - When the tools are mounted, ink is automatically transferred from the ink reservoir in the snap-on cap to the marking pad. The recessed marking pad is a unique design feature that ensures the surface remains free of unwanted marks while positioning the object. The only mark on the surface is the fastener location mark that comes from the push-to-mark action.  BUILT-TO-LAST: Commercial-grade Design using Metal Internal Components - Use for many years on any keyhole slot-enabled objects including Power strips, Surge protector, Floating shelves, Picture hanging (including on slanted walls), Corbels, Small parts organizer, Network switch, Power tool battery chargers, DIY keyhole router bits, Add-on keyhole slot hardware, etc. WARRANTY: 1 year